Ligand Effects and Ligand Design in Homogeneous Gold(I) Catalysis

Gold catalysis is considered one of the most important breakthroughs in organic synthesis during the past decade, but a rational understanding of ligand effects in gold catalysis is lacking. Most gold-catalyzed reactions go through three major stages: (i) electronic activation of alkyne (or allene) to generate a vinyl gold intermediate; (ii) protodeauration to generate the product and regenerate the cationic gold catalyst; (iii) decay of the active gold catalyst. Our research provides a clearer understanding of how ligands influence each of the three stages in the gold catalytic cycle. What is even more important, by not focusing on a particular gold-catalyzed reaction, we have been able to categorize most gold-catalyzed reactions and propose a ligand design protocol for each category of gold-catalyzed reactions

Enhanced Reactivity in Homogeneous Gold Catalysis through Hydrogen Bonding

Additives that are good hydrogen-bond acceptors increase the efficiency of gold-catalyzed reactions in those instances where protodeauration is the rate-determining step. The efficiency of additives capable of hydrogen-bonding-assisted protodeauration correlated with their standing in a scale of hydrogen bonding basicity (measured by p<i>K</i>_BHX). All additives used in the study are commercially available

Comparison of accuracy and feature dimension under different methods based on RFECV.

Comparison of accuracy and feature dimension under different methods based on RFECV.</p

Comparison of accuracy and feature dimension under different methods based on QPFS.

Comparison of accuracy and feature dimension under different methods based on QPFS.</p

EMD decomposition principle.

EMD decomposition principle.</p

The flowchart based on EMD with adaptive reconstruction.

The flowchart based on EMD with adaptive reconstruction.</p

Comparison of accuracy and feature dimension under different methods based on tree.

Comparison of accuracy and feature dimension under different methods based on tree.</p

The average classification accuracy versus the number of top-ranking features selected by mRMR, KCCAmRMR, QPFS, MIC and Tree and RFECV using RF classifier from our Lab data.

The average classification accuracy versus the number of top-ranking features selected by mRMR, KCCAmRMR, QPFS, MIC and Tree and RFECV using RF classifier from our Lab data.</p

Comparison of results using Yaseen database.

Comparison of results using Yaseen database.</p

Heart sound flowchart based on EMD adaptive HD reconstruction.

Heart sound flowchart based on EMD adaptive HD reconstruction.</p